package com.lagou;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;

import java.io.IOException;

public class SortDriver {
    public static void main(String[] args) throws IOException, ClassNotFoundException, InterruptedException {

        //获取配置文件对象，获取job对象实例
        Configuration conf = new Configuration();
        Job job = Job.getInstance(conf, "SortDriver");
        //指定程序jar的本地路径
        job.setJarByClass(SortDriver.class);
        //指定Mapper和Reducer类
        job.setMapperClass(SortMapper.class);
        job.setReducerClass(SortReducer.class);
        //指定Mapper输出的kv数据类型
        job.setMapOutputKeyClass(IntWritable.class);
        job.setMapOutputValueClass(NullWritable.class);
        //指定最终输出的kv数据类型
        job.setOutputKeyClass(IntWritable.class);
        job.setOutputValueClass(IntWritable.class);
        //指定job处理的原始数据路径
        FileInputFormat.setInputPaths(job, new Path("input"));
        //指定job输出结果路径
        FileOutputFormat.setOutputPath(job, new Path("output"));
        //8. 提交作业
        boolean flag = job.waitForCompletion(true);
        //jvm退出：正常退出0，非0值则是错误退出
        System.exit(flag ? 0 : 1);
    }
}
